That was the point of my post . I know the cams design and was suggesting that newer cams MAY , MAY be using a different lobe centerline, causing camsto wipe by not rotating the lifter . I do not have any new production after market cams to compare . I purchased dozens of different profiles 30 yrs ago when Crane cams was still local . Just uncovered a set of Fireball heads , anyone remember those ?
Flat tappet lifters today are junk, doesn't matter how much zinc or what oil it is, if the bottom is not machined and hardened correctly it's going to fail.
If true......amazing!! (The above video) To think the greed is at such a level that manufacturers would 'colude' with each other to keep the truth from being released! Could they 'really' be saving enough money, by re-machining old lifters, to make this a common practice? 6sally6 Looking at the MESS our country has gotten into recently......I don't know what or who to believe any more!
Lol,,,,,I seriously doubt that they are re working old lifters and selling them as new . For the reasons already ***igned,,,,,lack of old cores available . But even more,,,,is the cost involved . Would it be cheaper to pay someone to dis***emble old lifters and then machine them . Or is it cheaper to take a piece of bar stock,,,,,and load it in a CNC machine center and turn it on ? These machines can run day and night,,,,without anyone present if need be . My su****ion is skipping an essential step,,,,like a final machine cut to add the correct finish . Or,,,,,more likely,,,,,not correctly hardening the lifters face ! And inadequate hardening of the cams as well,,,,,a few numbers too soft can add up . Several numbers would be instant failure . I’m not certain,,,,,maybe some failures are supplier oriented,,,,,and some on the user end ? I’ve heard and read about cam and lifter failures since I was a kid . Tommy
Worked at a 'damned good garage' when I was an apprentice...in '57, we had a few International Harvesters flatten camshafts, (blown head gaskets, burned valves...) and some Y-block Fords (272, 292) flattened and broke cams. I recall pulling 4 cam pieces out the front with a 'Lizard Looper'. (large tube of radio antenna with a long loop of baling wire) But SBCs were coming in regularly with flat cams. (mostly 283s) When the 327 was out, cams were flattened early on. Fixed a lot of 'em...parts directly from Courtesy Chevrolet.
Perhaps this has been mentioned, please forgive me if it has, but are the flat tappet cam failures confined to mostly Chevrolet, or is this failure an equal opportunity offender? I’m not picking on any one auto maker, maybe we hear more about flat Chevy cams because it is the most popular engine around here? Other than IH when I fixed school buses, I don’t recall any other manufacturers having cam trouble.
To be fair,,,you’re probably right,,,,,,Chevy has sold a lot of engines . Which means a lot of cams have been swapped over the years . SBC is one of the most popular engines to be hot rodded over the last 60 years . It kind of took up where the Flathead left off . Of course the flathead didn’t really have any cam problems much . With the low spring pressure,,,,,and low lift . But I will bet the Ford cam hardening was not overlooked,,,,,,everyone was afraid of Mr Henry,,,,,he had more power than several Presidents then . Tommy
The flathead design has more going for it than a hardened camshaft. Low valve spring pressures and no multiplication of pressure by a 1.5 or 1.7 rocker ratio make them easy on the valve train.
I'm in the camp that believes there are a lot of variables playing into failure. Cheap cam, cheap lifters, AND THE BEST DAMN SPRINGS MONEY CAN BUY LOL! Listen, I'm a cheap *******, but i follow it through til the end. If I'm running exotic heads with the finest of everything, I'm not gonna stick a cheap CL kit in it. And if i stuck my "economically priced" camshaft in it, I'm not gonna put crazy pressure springs in my heads. Those later Chevy vortec heads, the good ones that everybody was hoarding up, do you think the majority of people know that they can't handle any lift unless you remove the valves and cut down the guides? The retainer hits the valve guide at around .470 if i remember correctly? I just think there is more to it than metallurgy. But then again, i paint cars.
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